Research will be undertaken to employ ion and gas sensing membrane electrodes for clinical analysis of substrates, enzymes, electrolytes, and other body fluid constituents. Methods will be developed for the determination of clinically important substances in serum, whole blood, and urine involving the employment of crystal membrane, enzyme coated and other electrodes in continuous analysis systems with capabilities of handling 100-200 samples per hour. It is expected that the proposed approach will result in desirable simplifications of the chemistries involved, by elimination of dialysis and color development steps, and will produce a significant reduction in analysis costs, by the elimination of expensive optical and electronic instrumentation as well as a reduction in the quantities and number of required reagents.